(a) Field of the Invention
The present invention relates to a heating substrate equipped with a conductive thin film and electrodes, and a manufacturing method of the same. More particularly, the present invention relates to a heating substrate equipped with a conductive thin film and electrodes and a manufacturing method of the same in which the electrodes are formed at the conductive thin film, and a current flows into the electrodes and the conductive thin film, thereby generating heat.
(b) Description of the Related Art
Generally, heat is generated by applying a current to a transparent conductive thin film, but heating value thereof is restricted by electrical resistance of a conductive thin film. In a heating apparatus that should generate a greater heating value, the limitation of the heating value by the electrical resistance can cause a decisive problem.
As an example, in a case of a heating apparatus that is manufactured by applying a conductive thin film on a polyester (PET) substrate and forming electrodes of a metal component, since the resistance of the conductive thin film is large, there is a limit to the increase of heating value.
In order to obtain a defrosting effect, the heating value should be sufficient to apply the heating apparatus to a broad area such as a front or rear window of an automobile. Particularly, the automobile generally uses a 12V voltage, so there is a limit to the increase of heating value.
Surface resistance of indium tin oxide (ITO), which is a material of a typical conductive thin film, can be changed from several ohms (Ω) to thousands of ohms (Ω) according to manufacturing conditions. However, a lot of costs and a fastidious process are required to lower the surface resistance to several ohms (Ω).
Furthermore, in a case of the thin film formed of carbon nanotubes or a conductive polymer, it is difficult to lower the surface resistance to hundreds of ohms (Ω) or less without impairing transparency as a whole.
Resistance magnitude is not a substantial issue in some application fields, but a great obstacle is occasionally caused in applying to a product to which a low resistance is required. Accordingly, a lot of research into lowering the resistance while maintaining transparency of the conductive thin film is currently being undertaken.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.